1. Field of the Invention
The present invention relates to a hard disk drive that has an integrated Helmholtz resonator which attenuates noise generated by the drive.
2. Prior Art
Hard disk drives contain a plurality of transducers that are coupled to magnetic disks. The transducers can read and write information by magnetizing and sensing the magnetic fields of the disks, respectively. The disks are rotated by a spindle motor that is mounted to a base plate.
The transducers are typically integrated into heads that are mounted to corresponding flexure arms. The flexure arms are attached to an actuator arm that is mounted to the base plate. The actuator arm includes a voice coil motor that can move the transducers across the surfaces of the disks. The voice coil motor allows the transducers to access information located within different radial tracks of the disks. The disks, spindle motor and actuator arm are all enclosed by a cover that is attached to the base plate.
The spindle motor and voice coil motor generate noise that is transmitted into the environment through the cover and the base plate of the drive. The spindle motor may also create vibration that is converted into acoustic noise and emitted by the drive. Additionally, the rotating disks create a flow of air that may generate fluid perturbations and resultant acoustic noise. Acoustic noise is undesirable particularly when the disk drive is assembled into a consumer product such as a computer or a digital video recorder.
Co-pending application Ser. No. 09/585,914 discloses a hard disk drive housing that attenuates acoustic noise generated by the disk drive. The housing includes multiple layers that can be designed to create a transfer function that attenuates, or rolls off, acoustic noise within a range of frequencies. The bandwidth of the metal laminate acoustic filter is relatively narrow. It would be desirable to provide a hard disk drive that attenuates the noise generated by the drive in a relatively broad bandwidth. It would be desirable to attenuate the noise without significantly increasing the size of the hard disk drive or the cost of producing the hard disk drive.
One embodiment of the present invention is a disk drive housing that can attenuate noise. The housing may include a first layer that is attached to a second layer, and a gap located between the first and second layers. The layers and gap may be configured to attenuate acoustic energy within a relatively broad frequency range.
FIG. 1 is a top sectional view of an embodiment of a hard disk drive of the present invention;
FIG. 2 is a side sectional view of the housing;
FIG. 3 is a top sectional view showing one embodiment of a gap in a hard disk drive housing; and,
FIG. 4 is a top sectional view showing another embodiment of a gap in the hard disk drive housing.